Direct Contact Evaporation of Refrigerant 113 in Distilled Water

1986 ◽  
Author(s):  
Choondal B. Sobhan ◽  
K. N. Seetharamu
Keyword(s):  
Direct Contact ◽  
Distilled Water

scholarly journals The Effect of Periogen Solution on Dental Calculus in vitro: A Pilot Study

2017 ◽  
Vol 6 (1) ◽  
pp. 33-34
Author(s):  
Marta Radnai ◽  
Zsolt Rajnics
Keyword(s):  
Pilot Study ◽  
Hydrochloric Acid ◽  
Acid Solution ◽  
Oral Hygiene ◽  
Direct Contact ◽  
Photometric Method ◽  
Distilled Water ◽  
Dental Calculus ◽  
Carbamide Peroxide

ABSTRACT Introduction Calculus can accommodate teeth and prosthetic restorations when the patient's oral hygiene is poor. Hardened calculus cannot be removed by patients, it needs professional cleaning using ultrasonic scaler or hand instrument. Solutions dissolving and preventing accumulation of dental calculus may help to keep dentures clean. The aim of this investigation was to examine the effect of Periogen on dental calculus in vitro. Materials and methods Calculus was collected via scaling from patients during a routine dental checkup. The samples were stored in carbamide peroxide solution (5%) for 24 hours, then rinsed and stored in distilled water. First, the Ca2+ content of the calculus was determined by photometric method after treating with cc. hydrochloric acid solution for 1 hour. The calculus samples were put in Periogen solution, prepared according to manufacturer's instruction for 16 hours, then crushed and put in Periogen solution with the same concentrate for 4.5 hours. The Ca2+ dissolved from calculus was measured using same photometric method. Results Calculus samples contained 26 mg/100 mg Ca2+, which is similar to dentin (27–28 mg/100 mg) and to enamel (36 mg/100 mg). The Ca2+ dissolved from calculus after treating with cc. hydrochloric acid for 1 hour was considered 100%. Ca2+ dissolution was 1.5% after 16 hours (0.09%/h) and 5.45% (1.21%/h) for the next 4.5 hours after pulverizing the sample. This showed Periogen Ca2+ dissolution was 385 µg/100 mg after 16 hours direct contact with the material. Conclusion The experiment showed that pulverizing the previously hard calculus was done easily after soaking it in Periogen. The ability of Periogen to soften the calculus needs to be further investigated. How to cite this article Rajnics Z, Radnai M. The Effect of Periogen Solution on Dental Calculus in vitro: A Pilot Study. Int J Experiment Dent Sci 2017;6(1):33-34.

Inhibitory Effect of Beta-Ionone on Growth and Aflatoxin Production by Aspergillus parasiticus on Peanuts1

1986 ◽  
Vol 49 (7) ◽  
pp. 515-518 ◽  
Author(s):  
CHENG-I WEI ◽  
HSIOUKUN TAN ◽  
SAMUEL Y. FERNANDO ◽  
NAN-JING KO
Keyword(s):  
Sodium Hypochlorite ◽  
Direct Contact ◽  
Mycelial Growth ◽  
Aspergillus Parasiticus ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Inhibitory Effect ◽  
Distilled Water ◽  
Antifungal Compounds ◽  
Treatment Conditions

The volatile ketone (β-ionone showed a dose-related inhibition of fungal growth and aflatoxin production on peanuts after they were soaked in distilled water for 25 or 50 min, inoculated with spores, and incubated at 28°C for up to 2 weeks. For example, aflatoxin B1 (AFB1) production after 1 week of incubation was reduced to less than 11.0 and 6.7% of the control when 2.5 or 5 ml of (β-ionone/100 g of peanuts, respectively, was added to water-soaked (25 min) peanuts. For AFG1, production was reduced to 4.7 (2.5 ml) or 3.3% (5.0 ml) under the same treatment conditions. Unlike controls or those treated with less than 0.1 ml of β-ionone, peanuts treated with more than 0.25 ml of β-ionone had only sparse mycelial growth and supported only limited sporulation. The mycelia, after being transferred to fresh Mycological or Fluorescent Agar plates, still had the ability to form normal colonies and produce aflatoxins. This temporary limitation of fungal growth was also noticed for those Aspergillus cultures on Mycological Agar that had been treated with (β-ionone either by direct contact or volatile bioassay procedures. The fungus was still able to grow of Fluorescent Agar even after the infected peanuts were treated with sodium hypochlorite for 15 or 30 min, indicating that mycelial penetration into peanut tissues occurs. This may confer protection from the action of various antifungal compounds. This observtion is further supported by microscopic detection of mycelial fragments in peanut tissues.

Direct Contact Evaporation Between Two Immiscible Liquids in a Spray Column

1989 ◽  
Vol 111 (3) ◽  
pp. 780-785 ◽  
Author(s):  
K. N. Seetharamu ◽  
P. Battya
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Direct Contact ◽  
Reasonable Agreement ◽  
Column Height ◽  
Phase Flow ◽  
Distilled Water ◽  
Operational Parameters ◽  
Immiscible Liquids

The present investigation deals with the direct contact evaporation of refrigerant 113 and n-pentane in a stagnant column of distilled water. The operational parameters investigated in the experimental study are the operating column height, the temperature difference, the dispersed phase flow rate, and the diameter and number of orifices in the distributor. The effects of these parameters on volumetric heat transfer coefficient, holdup, and agglomeration are investigated. A modified relation, based on the theoretical analysis of Smith et al. (1982), is also developed for predicting the theoretical volumetric heat transfer coefficient. Comparison with related works available in the literature shows reasonable agreement.

scholarly journals Impact of Hydrogel on Physical Properties of Coarse-structured Horticultural Substrates

1993 ◽  
Vol 118 (2) ◽  
pp. 217-222 ◽  
Author(s):  
W.C. Fonteno ◽  
T.E. Bilderback
Keyword(s):  
Hydraulic Conductivity ◽  
Physical Properties ◽  
Direct Contact ◽  
Total Porosity ◽  
Dry Weight ◽  
Pine Bark ◽  
Distilled Water ◽  
Polyacrylamide Hydrogel ◽  
Pressure Plate ◽  
Air Space

Addition of a polyacrylamide hydrogel to pine bark and pine bark + sand substrates had no effect on total porosity, regardless of incorporation rate. Container capacity was increased with increasing rate of hydrogel in both substrates. Air space in pine bark was slightly increased at the lowest rate but was reduced with higher incorporation rates. Air space in pine bark + sand was reduced with all hydrogel additions. The dry weigh', of hydrogel cubes recovered from both substrates was similar to amounts predicted. This result indicates that blending hydrogel granules into the substrates was uniform and did not contribute to variability in hydrogel studies. After allowing dry hydrogel granules to expand freely in distilled water for 24 hours, hydrogel granules expanded 317 and 372 times their dry weights at the lowest and highest rates, respectively. Reduction of expansion (in water) at higher rates may have been due to physical restriction of expansion. Conversely, recovered hydrogel cubes from substrates watered to drainage (-10% excess) for 6 weeks absorbed 25 to 55 times their dry weight while in the container. Subsequent rehydration of extracted gels in distilled water was greater for hydrogel cubes from the pine bark + sand medium (104 to 130) than in pine bark alone (51 to 88). Because of anomalies in hydraulic conductivity and pressure plate contact, three techniques were used to study unavailable water content in gels expanded in distilled water. Hydrogel cubes placed in direct contact with the pressure plate released ≈95% of their water at pressures ≤ 1.5 MPa. Effectiveness of ployacrylamide gels in coarse-structured substrates is influenced by physical restrictions to expansion in the substrate and hydraulic conductivity between the hydrogel cubes and the surrounding substrate.

Saturn's E, G and F rings: modulated by the plasma sheet

1984 ◽  
Vol 75 ◽  
pp. 597
Author(s):  
E. Grün ◽  
G.E. Morfill ◽  
T.V. Johnson ◽  
G.H. Schwehm
Keyword(s):  
Solar Wind ◽  
Direct Contact ◽  
Transport Processes ◽  
Time Variable ◽  
Dust Particles ◽  
Spatial Diffusion ◽  
Drag Forces ◽  
Orbit Perturbation ◽  
Time Variations ◽  
F Ring

ABSTRACTSaturn's broad E ring, the narrow G ring and the structured and apparently time variable F ring(s), contain many micron and sub-micron sized particles, which make up the “visible” component. These rings (or ring systems) are in direct contact with magnetospheric plasma. Fluctuations in the plasma density and/or mean energy, due to magnetospheric and solar wind processes, may induce stochastic charge variations on the dust particles, which in turn lead to an orbit perturbation and spatial diffusion. It is suggested that the extent of the E ring and the braided, kinky structure of certain portions of the F rings as well as possible time variations are a result of plasma induced electromagnetic perturbations and drag forces. The G ring, in this scenario, requires some form of shepherding and should be akin to the F ring in structure. Sputtering of micron-sized dust particles in the E ring by magnetospheric ions yields lifetimes of 102to 104years. This effect as well as the plasma induced transport processes require an active source for the E ring, probably Enceladus.

Biophysical Measurement of Molecular Weight of Foot-and-Mouth Disease RNA Fragments

1974 ◽  
Vol 32 ◽  
pp. 262-263
Author(s):  
Sydney S. Breese ◽  
Howard L. Bachrach
Keyword(s):  
Chemical Properties ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Distilled Water ◽  
Bovine Plasma ◽  
Mouth Disease Virus ◽  
Foot And Mouth ◽  
Carbon Coated ◽  
Rna Fragments ◽  
Physical And Chemical

Continuing studies on the physical and chemical properties of foot-and-mouth disease virus (FMDV) have included electron microscopy of RNA strands released when highly purified virus (1) was dialyzed against demlneralized distilled water. The RNA strands were dried on formvar-carbon coated electron microscope screens pretreated with 0.1% bovine plasma albumin in distilled water. At this low salt concentration the RNA strands were extended and were stained with 1% phosphotungstic acid. Random dispersions of strands were recorded on electron micrographs, enlarged to 30,000 or 40,000 X and the lengths measured with a map-measuring wheel. Figure 1 is a typical micrograph and Fig. 2 shows the distributions of strand lengths for the three major types of FMDV (A119 of 6/9/72; C3-Rezende of 1/5/73; and O1-Brugge of 8/24/73.

Freeze-fracture, freeze-etch complementary pairs of virus-infected cells reveal value of etching even when relatively high concentrations of cryoprotectants are used

1978 ◽  
Vol 36 (2) ◽  
pp. 136-137
Author(s):  
Russell L. Steere ◽  
Eric F. Erbe
Keyword(s):  
Plant Tissue ◽  
Phosphate Buffer ◽  
Infected Plant ◽  
Freeze Fracture ◽  
Distilled Water ◽  
Virus Infected Plant ◽  
Infected Cells ◽  
High Concentrations

It has been assumed by many involved in freeze-etch or freeze-fracture studies that it would be useless to etch specimens which were cryoprotected by more than 15% glycerol. We presumed that the amount of cryoprotective material exposed at the surface would serve as a contaminating layer and prevent the visualization of fine details. Recent unexpected freeze-etch results indicated that it would be useful to compare complementary replicas in which one-half of the frozen-fractured specimen would be shadowed and replicated immediately after fracturing whereas the complement would be etched at -98°C for 1 to 10 minutes before being shadowed and replicated.Standard complementary replica holders (Steere, 1973) with hinges removed were used for this study. Specimens consisting of unfixed virus-infected plant tissue infiltrated with 0.05 M phosphate buffer or distilled water were used without cryoprotectant. Some were permitted to settle through gradients to the desired concentrations of different cryoprotectants.

Comparison of Acrylamide and Agar Gels by Freeze-Etching

1977 ◽  
Vol 35 ◽  
pp. 606-607
Author(s):  
Russell L. Steere ◽  
Eric F. Erbe
Keyword(s):  
Electron Microscope ◽  
Sodium Hydroxide ◽  
Sodium Hypochlorite ◽  
Chromic Acid ◽  
Distilled Water ◽  
Thin Sheets ◽  
Acid Cleaning ◽  
Agar Gels ◽  
Freeze Etching ◽  
Water Cut

Thin sheets of acrylamide and agar gels of different concentrations were prepared and washed in distilled water, cut into pieces of appropriate size to fit into complementary freeze-etch specimen holders (1) and rapidly frozen. Freeze-etching was accomplished in a modified Denton DFE-2 freeze-etch unit on a DV-503 vacuum evaporator.* All samples were etched for 10 min. at -98°C then re-cooled to -150°C for deposition of Pt-C shadow- and C replica-films. Acrylamide gels were dissolved in Chlorox (5.251 sodium hypochlorite) containing 101 sodium hydroxide, whereas agar gels dissolved rapidly in the commonly used chromic acid cleaning solutions. Replicas were picked up on grids with thin Foimvar support films and stereo electron micrographs were obtained with a JEM-100 B electron microscope equipped with a 60° goniometer stage.Characteristic differences between gels of different concentrations (Figs. 1 and 2) were sufficiently pronounced to convince us that the structures observed are real and not the result of freezing artifacts.

Heterogeneity of Size and Distribution of Intramembrane Particles in the Plasma Membrane of Yeast

1977 ◽  
Vol 35 ◽  
pp. 596-597
Author(s):  
E. Keyhani
Keyword(s):  
Plasma Membrane ◽  
Candida Utilis ◽  
Synthetic Medium ◽  
Freeze Fracture ◽  
Translational Diffusion ◽  
Yeast Cells ◽  
Distilled Water ◽  
Intramembrane Particles ◽  
The Matrix ◽  
Water Cell

The matrix of biological membranes consists of a lipid bilayer into which proteins or protein aggregates are intercalated. Freeze-fracture techni- ques permit these proteins, perhaps in association with lipids, to be visualized in the hydrophobic regions of the membrane. Thus, numerous intramembrane particles (IMP) have been found on the fracture faces of membranes from a wide variety of cells (1-3). A recognized property of IMP is their tendency to form aggregates in response to changes in experi- mental conditions (4,5), perhaps as a result of translational diffusion through the viscous plane of the membrane. The purpose of this communica- tion is to describe the distribution and size of IMP in the plasma membrane of yeast (Candida utilis).Yeast cells (ATCC 8205) were grown in synthetic medium (6), and then harvested after 16 hours of culture, and washed twice in distilled water. Cell pellets were suspended in growth medium supplemented with 30% glycerol and incubated for 30 minutes at 0°C, centrifuged, and prepared for freeze-fracture, as described earlier (2,3).

Variations in Surface Textures of Quartz Sand using Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 494-495
Author(s):  
Eugene J. Amaral
Keyword(s):  
Electron Microscopy ◽  
Glass Industry ◽  
Glass Slide ◽  
Distilled Water ◽  
Early Paleozoic ◽  
Secondary Effects ◽  
Surface Textures ◽  
High Silica ◽  
Sand Deposit ◽  
The U.S

Examination of sand grain surfaces from early Paleozoic sandstones by electron microscopy reveals a variety of secondary effects caused by rock-forming processes after final deposition of the sand. Detailed studies were conducted on both coarse (≥0.71mm) and fine (=0.25mm) fractions of St. Peter Sandstone, a widespread sand deposit underlying much of the U.S. Central Interior and used in the glass industry because of its remarkably high silica purity.The very friable sandstone was disaggregated and sieved to obtain the two size fractions, and then cleaned by boiling in HCl to remove any iron impurities and rinsed in distilled water. The sand grains were then partially embedded by sprinkling them onto a glass slide coated with a thin tacky layer of latex. Direct platinum shadowed carbon replicas were made of the exposed sand grain surfaces, and were separated by dissolution of the silica in HF acid.

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